Transformation-Based Reconstruction for Real-Time Voice Transmissions over the Internet

In this paper, we explore the loss behavior encountered in transmitting real-time voice over the Internet and propose a new loss-concealment scheme to improve its received quality. One known technique to conceal loss is to send interleaved streams of voice samples and reconstruct missing or late samples by interpolation at the receiver. Based on this method, we propose a new transformation-based reconstruction algorithm. Its basic idea is for the sender to transform an input voice stream, according to the interpolation method used at the receiver and the predicted loss behavior, before interleaving the stream. The transformation is derived by minimizing reconstruction error in case of loss. We show that our method is computationally efficient and can be extended to various interleaving factors and interpolation-based reconstruction methods. Finally, we show performance improvements of our method by testing it over the Internet.